“It’s under deliberation of course, and it’s something that I had been looking at before Tom Harkin announced his retirement and now that that has happened, of course it accelerated the decision making process,” King said as he was leaving a Heritage Foundation-sponsored retreat for conservative Republicans in Baltimore.

“I don’t want to step into this thing and make an announcement in the face of the issue that Karl Rove has raised," he continued. "We’ve got to decide first who’s going to nominate people for public office in America: Somebody outside the state with a big checkbook, or the people of Iowa."

Law told The New York Times he’s worried that King may be too undisciplined to be elected statewide. Law is starting a new group, the Conservative Victory Project, to support the most seasoned and viable GOP candidates in primaries. Over the past two cycles, Republicans failed to win five Senate seats because of lackluster nominees in otherwise winnable races.

King sent a fundraising email after the story was published stating, “nobody can bully me out of running for the Senate.”

He followed up on Friday, telling CQ Roll Call that his successful 2012 race against former Iowa first lady Christie Vilsack, a Democrat, proved he is electable, and he and Rove will have to “fight it out in the court of public opinion.”

“This is a test case for the whole country,” King said. “We have to fight this out on this principle and when its clearly understood that the people within the state have the right and the duty to nominate their candidates, when that’s clearly understood, then I can take a look at the rest of the decision making process. I’m not going to be clouded by that.”